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Antenna rotator: how it work,how to repair and how to modify it

Dchematics and photos of a secure power supply (short-cut, Rf feedback, high voltage etc.) by iz7ath

Drawings and short descriptio in spanish for dipoles and bazooka antenna.

Web receiver of hb9afz-using icom pcr 1000 on weekends 0800-2000 utc.

This project uses a widely available IRF510 MOSFET, work on HF 80, 40, 30, 20 and 17 meter bands

This page describes the loading coil (inductor) that W8WWV built for my center-loaded 160 meter band (1.83 MHz) vertical antenna.

YAESU FT-1000/MP/MARK V (filed) interface, this one of numerous RTX sound blaster interfaces you can find on the internet, but this one include: FSK KEYING to use with the RTTY port, DVS-2 to use the interface in AFSK mode, this include all digital modes + voice keyer, CW KEYING

Complete tower system incorporates rotator mount, and lateral support collars. You never have to climb again - and forget the hassle of tilting over to work on large arrays. The "One Man Tower" is the strongest dmall footprint free standing self erecting tower in the world

Power and SWR Meter with dual bargraphs and sticky bar, using 2x AD8307

Inverted vee dipole antenna for 20 meters band by VK1OD

The most flexible and powerful Microwave and RF Filter and Multiplexer Design Software. Download Filpro-student.zip

A KD1JV Melt solder kit, a swr and power meter operating from 160 to 6 meters ideal for portable and field use

Demonstrates an online **CW** audio decoder tool, currently under active development, designed for analyzing and decoding Morse code. Users can upload audio files containing Morse code or record live audio input via a microphone, with processing handled entirely in JavaScript using the Web Audio API. The software analyzes the audio, attempting to determine the pitch and speed, and then decodes the message, providing options to compare the decoded output against a predefined message or a perfectly timed version. The interface allows for setting optional comparison messages, character speed in WPM, and Farnsworth speed. It also features interactive charts for visualizing the audio analysis, where users can zoom with the mouse wheel and pan by dragging. Specific buttons highlight different element types such as intra-character space, inter-character space, extra elements, missing elements, and replaced elements, aiding in detailed signal analysis. Built-in test files are available for immediate analysis, allowing users to quickly evaluate the decoder's performance. The tool is noted to work with specific browsers and is presented as a testing platform for user feedback, indicating ongoing refinement of its decoding algorithms and user interface.

This tower is easy and inexpensive to build and easy to disassemble for transport.

This project shows how to build a 50-ohm dummy load using non-inductive resistors, oil for heat dissipation, and a simple assembly process. It enables accurate transmitter tuning, testing, and power measurement across LF to UHF bands. The setup allows meter calibration by measuring peak voltage, applying diode drop correction, and calculating RMS voltage and power precisely. Parts are inexpensive and widely available. With proper assembly, this dummy load offers extended service life, accurate readings within 2%, and a reliable alternative to costly commercial wattmeters for amateur radio applications.

University of Texas Amateur Radio Club RF-Calculator. This is a main beam power density estimation program intended for use as part of a routine evaluation of RF safety compliance with FCC regulations

The G3TPW Cobwebb antenna covers five bands, 14 - 28 mhz, including the WARC bands

Method of storing my portable wire antennas.

2-Element parasitic Yagis for the Shortwave-Bands 10m-30m

Program designed to do spectral analysis and real-time audio filtering on reception of audio signals for EME, VLF, SETI applications. Offer support for MTHELL, QRSS, DFCW, NDB, WSJT by I2PHD

Allow you to create Tower Coverage Maps for any geographical area in the entire world. Maps are based on region and topography, taking into account for hills, mountains and trees. Commercial software allowing a free map trial

Article and comparison between bazooka antennas and dipole, taking care of effieciency and bandwidth

A homemade 16 foot falling derrick to tilt up a 50 foot high, 18 inch wide Glen Martin aluminum tower by N6RK

Amateur Radio G3TXQ Cobweb Antenna a 5 band antenna that can be quickly assembled.

W3FF article about the buddistick portable vertical antenna in a PDF file

Simple eprom programmer for 27Cxx family , used in TNC and G3ruh modem, eprom tutorial, schematics and KissEprom software for windows by iz7ath

OZ2OE Technical pages, a 3 element 28 MHz light weight Yagi for 10 meters band

Argo, developed by I2PHD and IK2CZL, functions as a specialized freeware viewer for various weak signal modes, specifically MTHELL, Slow CW, QRSS, and DFCW. It processes audio input to visualize and decode these extremely low-speed transmissions, which are often imperceptible to the human ear. The software's capabilities extend to EME (Earth-Moon-Earth) operations, where its sensitivity to weak signals is particularly advantageous for detecting faint lunar reflections. The application provides a visual representation of the received signals, allowing operators to discern patterns and decode information from signals buried deep within the noise floor. Its design focuses on extracting data from signals with very narrow bandwidths and long integration times, characteristic of QRSS and similar modes. This tool is distinctively useful for experimenters and DXers engaged in challenging weak signal communication, offering a dedicated platform for modes not typically supported by general-purpose digital mode software. Its specialized focus on _Slow CW_ and _MTHELL_ makes it a niche but effective utility for specific operating scenarios.

Esr meter to measure the equivalent serie resistance of capacitors

How to make a Weatherproof Vertically Polarised Omnidirectional Aerial, The Slim Jim Antenna

A rotary trapped-dipole for 17 and 20 meters, as described by IZ7ATH, presents a practical solution for multi-band HF operation. The author, Talino, recounts his experience building this antenna for IK7ZCQ, detailing the evolution from an initial concept involving a grounded-driven element and gamma-match to a direct-fed, non-grounded design. His pragmatic approach, adapting available materials, is evident throughout the construction narrative, particularly with the use of eight tapered aluminum pipes for the driven element. Construction specifics include precise measurements for the aluminum tubing, with diameters ranging from 30 mm down to 16 mm, and a critical note on reducing tip thickness for weight optimization. The _traps_, initially a concern, are fabricated using 8 turns of RG58 coax on a 27 mm support, tuned to resonate at 18.1 MHz using a dip-meter. Talino emphasizes sealing the traps with RF glue and PVC tape to prevent water ingress, a crucial step for longevity. Field test results, conducted on a 10-meter pole in a clear garden environment, showed an SWR of 1.2:1 on 17 meters and 1.5:1 at 14.200 MHz. While SWR varied slightly when installed at Mario's QTH due to nearby objects, the antenna's performance remained commendable. The final half-dipole length is 46 cm for the 18 MHz tips, and the total weight is under 6 kg, with potential for further reduction.

OE4RLC, OE3DUS in Allhau Austria with wire antenna and full HF amateur radio bands coverage

Article on building a folded bazooka antenna

AM/FM/CW QRP RF Power Amplifier for the HF 10 or 11 meterband (28MHz/27MHz)

Live scanner feed

The page provides detailed instructions on how to build a double bazooka antenna for the 40 meters band. It includes information on materials needed, measurements, and assembly steps. The antenna can be configured as an extended dipole or an inverted V, offering low noise, wide bandwidth, and a 1:1 standing wave ratio. The content also offers calculations for other bands and includes photos of the antenna fabrication process.

adsbScope is a freeware Windows application designed for processing _ADS-B_ (Automatic Dependent Surveillance-Broadcast) frames received from a compatible decoder. It identifies aircraft, calculates their real-time positions, and presents flight parameters in both alphanumeric tables and a graphical display. The software interfaces via a virtual COM port, receiving raw frames to provide detailed situational awareness, including a global coordinate grid, continental coastlines, over 4,000 **airport** locations, and major cities. Users can overlay OpenStreetMap tiles and view world state boundaries, with each tracked aircraft rendered with labels showing altitude, speed, heading, squawk code, and flight identifiers. When paired with the adsbPIC-decoder, adsbScope enables advanced hardware control, allowing users to toggle data filters for specific frames like DF17/18/19, adjust analog signal thresholds for reception fine-tuning, and manage system resets or bootloader activation directly from the PC. This functionality provides a customizable toolkit for hobbyist radar listeners, offering a robust alternative to commercial tools for processing aircraft data. The software displays up to **1090 MHz** transponder data and can track aircraft up to 250 nautical miles.

Dedicated to Yaesu FT847 with mods infos and links... by F1MDT

Modification to the Bearcat 210 scanner for reception of 137 Mhz FM is a fairly simple process.

1500 Watt HF power amplifier

If you have ever tried transmitting on HF from a tall block of apartments, where it's just not possible to erect a substantial aerial system, then this article is for you

Collectible,antique, Radio Tubes, special purpose and audio electron tubes and literature.

On-line single-layer coil designer

Demonstrates a **DX cluster** web service providing real-time amateur radio spot reports, propagation information, and solar data. The platform integrates features such as a gray line map, **DXCC** tracking, and a personal logbook, allowing users to manage their confirmed entities and contacts. It supports various bands from 160m to 70cm, including specific filters for modes like FT8/FT4, and offers both web and Telnet access for spotting and monitoring. The service provides graphical representations of spot reports, detailing activity across different frequency bands and modes (CW, SSB, digital). Registered users gain access to advanced functionalities, including personalized filters and tools for calculating DXCC status. The platform also includes a classifieds section and options for mobile access, catering to a broad range of amateur radio operators interested in DXing and contesting.

YU1AW project for a home made QRO PA 144 MHz 20 kW GU36B-1

Constructing a high-power solid-state amplifier for HF operations presents unique challenges, particularly when aiming for significant output like 600 watts. This project details an amplifier design employing **Motorola MRF150** FETs, a common choice for their robust performance in RF power applications. The design emphasizes achieving substantial power output, a critical factor for effective DXing and contesting, where every decibel can make a difference in signal propagation and readability. While specific circuit diagrams or construction details are not directly presented on the current page, the mention of MRF150 FETs points towards a design that would typically involve push-pull configurations, impedance matching networks, and robust power supply considerations to handle the high current demands. Such amplifiers are often built with an eye towards linearity and efficiency across the HF bands. Amateurs pursuing similar high-power solid-state projects often share insights on thermal management, intermodulation distortion, and component sourcing, all vital for a stable and reliable amplifier capable of delivering 600 watts into a proper antenna system.

Icom PCR 1000 at NASA Marshall Space Flight Center monitoring meteor signals on 67.3 mhz.live.

JTDX is an open-source software application for amateur radio weak-signal digital communication. It supports digital modes including FT8 and JT9. The software operates on _Windows_, _Linux_, and _macOS_ platforms. JTDX is designed for improved decoding of weak signals, a function also performed by WSJT-X and MSHV. The software facilitates weak signal decoding and transmission. It integrates with logging systems for QSO management and can automate tasks such as call management and remote RTX control. JTDX is utilized in contexts such as DXing and contests. DXZone Focus: FT8 | JT9 | Weak Signal | Multi-platform

Freeware Hellschreiber decoding program for windows by Nino Porcino

Based on VK5BR's Z-Match and designed for High RF Power covers 160 to 10 meters by VK6YSF